You can see Vader's helmet shaking because of the wind when he tell's to luke "...rule the galaxy as father and son." the helmet should be fixed.
Good eyes. I must say that mistakes happen though. I find it pretty cool when someone else or even I find a mistake in a movie, video game, and even the newspaper.
~Rev
Maybe he was just moving his head slightly when he was making that statement....? It was a bold statement, after all.
It's because its a plastic prop balanced on his head, but they have you believe its some kind of fibreplast shell, with an airtight neck seal, encasing his burnt cranium :D
That part of the mask is only to protect the back of his head - it doesn't help him breathe at all - the front bit with the visor and respirator is what helps him breathe. That back part is really decoration.
Sorry if you weren't talking to me, but who said anything about helping him breath? I was trying to explain that the equipment and props are much more flimsy than the close up shots and "The Visual dictionary" would have you believe :)
Don't worry, I wasnt talking to anyone in particular, I was just saying that the back of the helmet is just for show.
:)